How to make a magnetic bookmark

If you know me you know I love books and I go through a bagilion post-its marking pages of things I want to make. So when Cryrstal of the blog Make It Easy Crafts sent in a link to her felt and tp tube napkin rings I did a little surfing around her fun blog and I spotted this tutorial on how to make a magnetic book mark. She made it with magnetic sheets but I have a stash of magnetic business cards that I am going to try this with.